Abstract We use a coupled land‐surface‐atmosphere single‐column model to examine the effects of deforestation and changed advective moisture flux (AMF) on the Amazonian system. We find that from current conditions, a reduction to 35% forest cover, or a ∼10% decrease in AMF (∼6% less precipitation), causes the system to transition from a wet climate with rainforest to a drier climate with savanna‐like vegetation. The system responds highly non‐linearly to the combined influences of the AMF and deforestation. Small changes in either forest cover or moisture advection are capable of causing the system to flip abruptly between stable forest, savanna, or shrubland states. Model behavior is strongly influenced by the feedback between the land surface and the atmosphere, with natural vegetation changes playing a major role. Our results suggest that continued deforestation is likely to trigger a transition to a savanna‐like state across Amazonia within this century under current climate projections.